Magnetic reversing and speed-varying gear clutch



E. J. MURPHY. MAGNETIC REVEBSING AND SPEED VARY iNG GEAR CLUTCH.

APPLICATION FILED MAR. 3| I920.

Patented Oct. 25, 1921.

2 SHEETS-SHEET l.

v Invento Edwih J. murphy, by jaw-6. 4

His Attor ney.

E. J. MURPHY.

MAGNETIC REVERSING AND SPEED VARYING GEAR CLUTCH. APPLICATION FILED MAR.3. I920.

Patented Oct. 25, 1921. F 2 SHEETSSHEET 2.

Inventor:

EdwinJmur-phy, b 4 49% His ffttorney.

- UNITED STATES PATENT OFFICE.

EDWIN J'. MURPHY, OF SCHENECTADY, NEW YORK, ASSIGNOR TO COMPANY, ACORPORATION OF NEW YORK.

GENERAL ELECTRIC MAGNETIC REVERSING AND SPEED-VARYING GEAR CLUTCH.

Specification of Letters Patent.

Patented Oct. 25, 1921.

Application filed March 3, 1920. Serial No. 363,056.

T all whom it may concern Be it known that I, EDWIN J. MURPHY, a citizenof the United States, residin at Schenectady, county of Schenectady,tate of New York, have invented certain new and useful Improvements inMagnetic Reversing and Speed-Varying Gear Clutches, of which thefollowing is a specification.

My invention has reference to improvements in magnetic reversing andspeed varying gear clutches. More particularly, my invention hasreference to electromagnetic gear clutching and reversing mechanism bymeans of which. a driving shaft rotating with constant speed in onedirection transmits motion to a driven shaft in the same or reversedirection with variable speed. This ll accomplish by both revolving androtating a system of magnetic rollers connected to "the driving shaft,on the surface of an annular magnetic toroid connected to the drivenshaft. The toroid may be of any suitable type, such as spheroidal,parabolic, hyperbolic, or polygonal, and 1 do not limit my invention toany particular type. The

flux path of an electromagnet is through the toroid and rollers whichgives a good frictional clutching engagement between these members. Thespeed and direction of rotation of the toroid is dependent upon thepoints of engagement between the toroid and the rollers. The points ofengagement may be shifted by moving the toroid in the direction of thedriving shaft, and in this manner the driven shaft may be caused 'torotate in either direction at the desired speed, or to remainstationary.

In the accompanying drawings, which form a part of this specification,one of the many forms which my invention may assume is illustrated asfollows:

Figure 1 is a front elevation partly in section; Fig. 2 is an end viewof l ig. 1; Fig. a reproduction of a portion of Fig. 1, with thestructural dimensions indicated, and Fi 4 is a perspective view of oneform of toro d used with my invention.

' Referring to the drawing, a magnetic frame 1, supported by a base 2,has an overhanging annular flange 3 at one end, which formh a housingfor a magnet coil 4, which latter is suitably mounted and insulated fromthe frame, as shownin Fig. 1. The opposite end of the frame, indicatedby the numeral 5,-ia cylindrical and has a central bore which extendsclear through this portion of the frame into said housing and in whichis fitted a sleeve 6 of non-magnetic material which serves as a bearingfor a cylindrical magnetic member 7. The member 7, which is journaleolin said bearing, extends at one end into the housing formed by theflange 3 and the other and extends out of the casing a suitable distancein the opposite direction. The end of the member 7 progecting into thehousing passes through the center of the magnet coil 4, thusconstituting a magnet core, and terminates in an annular toroid 8, whichis convexly curved outwardly from its axis, which latter coincides withthe axis of cylinder 5 and of member 7, and

it curves toward the edge of the flange 3.

The purpose of the annular toroid will more fully appear hereinafter.The toroidal surface shown in the drawing is supposed to be circular inthe line of its axial section. This means that it has been generated bythe rotation of a segment of a circle about an axis in its own plane.But for the purposes of my invention it is not essential that thetoroidal surface be thus generated; it may be generated by the properrotation of a segment of an.ellipse, or of a parabola, or hyperbole, andit may 8180 be formed by the proper rotation of any proper curve that isnot a conic section. In fact the conoid might be formed by the properrotation of a segment of a regular or even irregular polygon. As hasbeen indicated, and as will more fully appear hereinafter, the points ofcontact of the toroid with certain rollers which will presently bedescribed determine the and the gradation of speed of the driven.

shaft -'is consequently determined by the peculiar surface of thetoroid. It will be seen from this that great latitude of choice as tothe particular formof toroid is permissible. At its opposite end, themember 7 has a spiral gear 10 keyed or otherwise rigidly secured theretoin any suitable manner, which gear meshes with a pinion 11 of a drivenshaft 12. An axial bore 13extends through the member 7 in which isjournaled the driving shaft 14. The latter shaft is driven through gears15 and 16 by a suitable source of power connected to the shaft 17. I

The driving shaft 14 occupies a central position with respect to thetoroid 8 and to smaller a the annular flange 3. At its-end, projectingthrough the toroid '8, the shaft 14 has a U- shaped member 18 whichsupports a pin 19 at rlght angles to the-shaft 14. Two pins 20, 21 arepivotally mounted on the pin 19 by the terminal cars 20' and 21', andthe members 20, 21 freely support tworollers or spools 22, 23, which areof magnetic material. The free ends of the members 20, 21 are threadedso that the rollers 22, 23 may be secured in position, washers 24, 25and nuts 26, 27, being used for this purpose. The ears 20, 21 are eachprovided with arms 28, 29, respectively, and between them is anexpansion spring 30 which holds the members 20, 21 apart and preventstheir dropping to the position they would normally assume by gravity, iffree to move, and also urges them against the surface of the toroid 8.In case the axis of the toroid is vertically disposed, the spring 30 isnot necessary.

The rollers 22, 23 have enlargements 31, 32, respectively, at theirouter ends, and these enlargements are arranged to bear frictionally onthe edge of the flange 3. The

bear at some point C on a zone of the toroid 8, such as is indicated bydotted line 8' in Fig. 4, and thispoint of contact may be shifted bylongitudinally moving the member 7. A portion of the cylindrical end 5of the frame 1 is internally threaded and the member 7. carries a sleeve33 which is threaded at one end on its outer surface, to fit theinternally threaded portion of the frame. A creased in size forming ashoulder 34 to be engaged by the end of sleeve 33 when the latter ismoved. Ball bearings 35 are preferably placed between the shoulder 34and the end face of sleeve 33 to decrease the friction between them. Atits opposite'end the sleeve 33 is formed as a spiral gear 36 which.

. A-stop collar 40 is' adjustably. secured to the member 7 to limit themovement of the sleeve 33 in the-direction away from the frame- 1. Itis, therefore, obvious that the longitudinal movement of the member 7,which determines the point of contact between the rollers 22, 23 and thetoroid 8, is accomplished by turning the hand wheel 39 in the desireddirection.

By the longitudinal movement of the member 7, as controlled by the handwheel 39, the toroid is'moved forward or backward as thecase may be, therollers 22, 23 always bearing upon the surface of the toroid, while thepoints of contact are shifted. It

i should be observed that this shifting of the points of contactof twofriction gears, parparts of the rollers 22, 23 always portion of themember 7 is deticularly when they are clutched magnetically, should notbe effected by sliding one of the members upon the other, since suchsliding shift is objectionable on many accounts and particularly becauseit requires the application of considerable force. In the constructionhere shown the shifting of the contacts between the rollers and thetoroid is accomplished by a rocking motion of either or both the rollersand the'toroid and only a small force is required for this purpose.

A good clutchingengagement between the rollers 22, 23 and the toroid 8is secured by energizing the coil 4. The path of the flux thereby set upis through the member 7 which serves as the core of the magnet, thetoroid 8, the rollers-'22, 23, and the enlargements 31, 32, the flange3, the cylindrical end 5 of the casing, across the small reluctance gapformed by non-magnetic lining 6 to the core member 7 It is desirable tomake the gap between the edge of the toroid 8 and the flange 3 as wide,as possible in order to diminish there the unavoidable leakage flux, sothat practically the whole flux passes in the manner described throughthe rollers 22, 23 and the enlargements 31, 32.

In operation the driving shaft 14 is rotated with uniform speed whichmay be assumed to be n revolutions per unit of time, which of coursemeans that the rollers 22, 23 with their enlargements 31, 32 willrevolve n times er unit of time about the axis of shaft 14. The magnetcoil is'kept energized so that the rollers will firmly bear upon somepoint C on a zone .on the surface of the toroid, while the enlargementswill bear upon the edge of the stationary element, the edge of flange 3,whereby the rollers are rotated about their axes.

' A clear distinction must be made between the movement of the rollersabout the axis of the shaft 14 and about their own axes. The movement ofthe rollers about the axis of the shaft- -14 is in the proper andmathematical meaning 9. revolution while the movement of the rollersabout their own axes is I in the proper and mathematical meaning arotation. The combined revolution and rotation' is spoken of in the artas a planetary movement. ments, each separately considered, upon thetoroid are qulte disti ct from each other, and the combined of resultanteffect upon the toroid is the gist of this invention, as

will presently appear.

Referring now particularly to Fig. 3,-and designating by a, the distanceof the edge of the flange from the axis of the shaft 14; by 1', theradius of the enlargements 31, 32; by r, the radius of each of therollers 22, 23, and by b, the distance of the points C from the axis ofthe shaft 14; the surface The effects f the two movespeed of any of theenlargements, say 32, about axis 14 will be The corresponding surfacespeed of the roller 23 about its own axis is then I 2 mm,

and this is also the speed which, the roller tends to impart to thetoroid at the point C in the opposite direction. The actual or resultingsurface speed V of C is consequently This difference may be positive ornegative. If it is positive the toroid will be driven in one directionand if it is negative the toroid will be driven in the oppositedirection. In this expression 5 is the only variable quantity and if Tthe resulting speed of thetoroid at the point C is zero. There is alwaysa point on any convex toroid at which I than a. If I) is larger than 11,then the toroid will rotate in one direction and if b is smaller than athe toroid will rotate in'the iopposite direction, and the speeds of therotation will vary in direct ratio with 'b.

It is practicable to determine in advance form of the surface of thetoroid required 'for the desired surface speed of the latter at thedifferent points of contact with the same of the rollers 22, 23; becausethe quantity b may be computed for any desiredsurface speed from thefundamental equation, namely:

ous details of construction herein described may be variously changedwithout departing from my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, 1s,

1. The combination of a magnetic annular toroid and a driven shaftconnected there- ,with, of a driving shaft and a system of magneticrollers carried by the same, and

an electromagnet coil in position to magnetically clutch the rollerstothe toroid.

2. The combination of a magnetic frame with a magnetic annular toroidjournaled therein and connected to a driven shaft, of a system ofmagnetic rollers constantly rotated in one direction, and anelectromagnet coil in position to ma netically clutch the rollers to thetoroid an to the frame.

3. The combination of a magnetic frame with a magnetic annular toroidjournaled therein and connected to a driven shaft of a driving shaftconstantly rotated in one direction and carrying a system of magneticrollers, an electromagnet coil in POSltlOIli to magnetically clutch saidrollers to the toroid and to the frame, and means for shifting thetoroid zone of magnetic contact between the rollers and the toroid byrocking, as distinguished from sliding one or both contacting elementswith reference to the other. I,

4. The combination of a magnetic frame with a magnetic annular toroidjournaled therein and connected to a driven shaft, of

a driving shaft constantly rotatedin one direction and carrying a systemof magnetic rollers, and electromagnet coil in position to magneticallyclutch said rollers to the toroid and to the frame, and means forshifting the toroid zone of magnetic contact between the rollers and thetoroid.

5. The combination of a magnetic frame with a magnetic annular toroidjournaled therein connected to a driven shaft, o'f a system of magneticrollers constantly rotated in one direction, an electromagnet coil inposition to magnetically clutch the rollers to the toroid and to theframe, and means for shiftingthe toroid zone of ma etic engagementbetween the rollers and t e toroid.

6. The combination of a magnetic frame With a driving shaft constantlyrotating in one direction and actuating a system of magnetic rollers, ofa driven shaft connected to iamagnetic annular toroid concentric withthe driving shaft and journaled in the frame, an electromagnet coil inposition to magnetically clutch the rollers to the toroid and to theframe, and means for shifting the zone of'engagement between the rollersr and the toroid.

In witness whereof, have hereunto {set my hand this first day of March,1920. It will be readily understood that numer- EDWIN J. MURPHY.

